Method for preparing aerosol antiperspirant compositions

ABSTRACT

This invention is directed to a method a preparing aerosol antiperspirant compositions containing an alkoxy aluminum chloride as the antiperspirant, and to aerosol antiperspirant compositions so prepared, said method comprising the formation of the alkoxy aluminum chloride within the aerosol container from the reaction of an alkyl aluminum chloride with an appropriate alcohol, the alkane second product of the reaction serving, either alone or in part, as the propellant for the aerosol.

United States Patent 3,568,394 METHOD FOR PREPARING AEROSOL ANTIPERSPIRANT COMPOSITIONS Elly T. Margolis, Los Angeles, Calif., assignor to Dart Industries Inc., Los Angeles, Calif. No Drawing. Filed Aug. 24, 1967, Ser. No. 662,886

Int. Cl. A611 3/00; A61k 7/00; B6511 47/20 U.S. Cl. 53-21 1 Claim ABSTRACT OF THE DISCLOSURE This invention relates to a method of preparing aerosol antiperspirant compositions, and to aerosol compositions so prepared.

In particular the invention relates to a method of preparing aerosol antiperspirant compositions which comprises the chemical synthesis of the antiperspirant within the aerosol container through a chemical reaction wherein the by-product of the reaction serves, either wholly or in part, as the propellant for the aerosol. The invention also relates to aerosol antiperspirant compositions prepared by this method.

There are numerous causes for hyperhidrosis, the condition manifested by the involuntary delivery from excretory and apocrine glands of excessive amounts of perspiration to the surface of the skin. The condition often arises in response to emotional, thermogenic or pathological factors..But, whatever the reason for its origin, the social problems created are the same. Hyperhidrosis is disagreeable and annoying; the exudate is almost always malodorous and damage to wearing apparel through staining is an almost inevitable consequence.

To alleviate this condition, a variety of substances have been applied to the skin by assorted methods of administration, including administration in the form of solutions, ointments, creams, skin lotions, aerosols, powders, Wax sticks and the like. Among the most satisfactory of these substances are alkoxy aluminum chlorides which are most suitable administered in the form of aerosols.

In preparing such aerosol compositions the active ingredient alone, particularly if in the form of a liquid, or the active ingredient and the propellant, are cooled down to such a low temperature that they can, in liquid form, be introduced into the aerosol container. The container is then sealed, and when the temperature rises a suitable pressure is obtained within the container. Alternatively, the active ingredient is introduced into the container, the container is sealed, and the propellant then introduced through a valve under pressure.

One of the objects of this invention is to provide a method of preparing aerosol antiperspirant compositions that is economical and simple to carry out, requiring the mixture of as few as two substances to prepare both antiperspirant and propellant.

It is also an object of this invention to provide a method of preparing an aerosol antiperspirant composition that eliminates wholly or in part the use of expensive propellants.

A further object of the invention is to provide economi- 3,568,394 Patented Mar. 9, 1971 cally and easily prepared aerosol antiperspirant compositions.

Other objects and advantages of this invention will become apparent to those skilled in the art in the light of the following description, wherein the manner and process of making and using the invention will be generally described so as to enable one skilled in the aerosol art to make and use the same.

The antiperspirant component of the aerosol compositions according to this invention are alkoxy aluminum chlorides. These compounds are particularly useful in the control of hyperhidrosis in that they permit the preparation of completely anhydrous perspiration-inhibiting compositions. They are, therefore, especially suitable for aerosol administration. Moreover, the alkoxy aluminum chlorides, in contrast to other aluminum salts frequently employed in antiperspirant preparations, have only a slight tendency to crystallize. Thus, after administration in the form of an aerosol, when the propellant has volatilized they do not crystallize on treated body areas after application, but form, instead, a flexible film which guarantees a prolonged and better antiperspirant effect than other agents which display pronounced crystalline properties. In addition, alkoxy aluminum chlorides are completely soluble in low-boiling liquefied alkanes.

The propellant system used in the compositions according to this invention is based upon low-boiling liquefied alkanes as the pressure generating components. Such low-boiling liquefied alkanes are well known in the aerosol art as suitable propellants for pressurized compositions. The use of such alkanes or mixtures thereof results in lower production costs. Not only are these alkanes less expensive than the more commonly used propellants, but, being of lower specific gravity, they reduce substantially the over-all weight of the finished product and thereby effect savings in the cost of shipping.

Among the low-boiling liquefied alkanes that are useful as propellants are those which alone or as mixtures at 70 F. have a vapor pressure of at least 20 pounds per square inch gauge, but not more than 40 pounds per square inch gauge. Alkanes yielding such vapor pressures alone at 70 F. are butane and isobutane. Mixtures of alkanes yielding such vapor pressures at 70 F. are mixtures of butane and isobutane, and mixtures of alkanes yielding vapor pressures of less than 20 pounds per square inch gauge at 70 F. with alkanes yielding vapor pressures of more than 45 pounds per square inch gauge. Among the latter are mixtures of hexane and propane; pentane and butane; hexane, butane and propane; and the like. The desired vapor pressure is dependent upon the proportionate amount of each of the specific alkanes present in the mixture, and such proportions are readily determined by methods familiar to those skilled in the art.

Among the alkoxy aluminum chlorides which are especially useful as antiperspirant agents are alkoxy aluminum sesquichlorides, monochlorides and dichlorides wherein the alkoxy moiety is a straight or branched chain alkoxy group containing up to 18 carbon atoms. The preferred alkoxy aluminum chlorides are those wherein the alkoxy moiety contains from 3 to 12 carbon atoms.

The most convenient method for preparing such alkoxy aluminum chlorides comprises the reaction of an appropriate lower alkyl aluminum chloride with a monoatomic alcohol, the nature of the alkoxy moiety in the product being dependent upon the nature of the alcohol used in the reaction. The by-products of such reactions are low-boiling alkanes such as hereinabove described as being useful in the propellant system. The al'kane product produced in the reaction corresponds to the lower alkyl moiety of the alkyl aluminum chloride starting material. Thus, suitable alkyl aluminum chlorides include monoand di-lower alkyl aluminum sesqui-, monoand dichlorides wherein the alkyl moiety is propyl, isopropyl, butyl, tert-butyl, pentyl, hexyl and the like. Such alkyl aluminum chlorides may be present singly, to yield a single alkane, or as mixtures to yield suitable mixtures of alkanes. Use of a di-alkyl aluminum chloride in the reaction is preferred since it results in the production of two moles of the alkane propellant for each mole of alkoxy aluminum chloride antiperspirant. In practicing the method according to the present invention, therefore, at least one mole of the alcohol must be present for each alkyl radical present as part of the alkyl aluminum chloride used. Where excess alcohol is present, it serves as additional solvent for the antiperspirant.

In acrrying out the method according to the present invention the alcohol is placed in the aerosol container, the cap containing a valve is crimped onto the container, and the alkyl aluminum chloride is then introduced into the container through the valve. Of course, if preferred, the alkyl aluminum chloride may first be placed in the container and the alcohol added through the valve. Atternatively, the valve may be crimped onto the container first with the alcohol and alkyl aluminum chloride then successively introduced into the container. The order in which the ingredients are introduced into the container is immaterial provided the valve is affixed at some point prior to introduction of the last ingredient.

The pressure developed within the aerosol container is dependent upon the particular alkane produced in the reaction within the container and upon the quantity of said alkane present. Accordingly, it may be desirable upon occasion to introduce additional quantities of the alkane into the container or employ mixtures of alkanes in order to obtain an optimal pressure for the propellant system. A composition containing a mixture of alkanes may be formed by employing a mixture of alkyl aluminum chlorides, such as, for example, propane and butane being formed by reaction of an appropriate alcohol with propyl aluminum chloride and butyl aluminum chloride. Alternatively, the second alkane present may simply be added to the composition in pure form. For example, di-isobutyl aluminum chloride is commercially available in the form of a hexane solution. When used in this form the solution provides both the alkyl aluminum chloride and an alkane. Such alkyl aluminum chlorides may also be introduced as solutions in other alkanes. In addition, if desired, conventional propellants such as, for example, one of the halogenated lower alkanes may be added to adjust propellant pressure. Such compositions, wherein additional alkane or conventional. propellants have been introduced into the aerosol container, as well as compositions containing mixtures of alkanes are the full equivalents of the specific compositions wherein a single alkane has been formed and are included within the scope of this invention.

Because the lower alkanes that are suitable as propellants according to the present invention are generally quite flammable, it is often desirable to include in the propellant system a flammability-suppressing substance such as, for example, chloroform, methylene chloride, trichlorofiuoromethane and the like, or mixture thereof.

Alkyl aluminum halides other than the chloride may be substituted for the specific alkyl aluminum chlorides referred to hereinabove. Their use results in antiperspirant compositions wherein the halide moiety of the alkoxy aluminum halide corresponds to that present in the alkyl aluminum halide employed. Such halides include the bromide, fluoride and iodide, and are included within the scope of this invention.

The best mode contemplated by the inventor for carrying out the invention will now be set forth as follows:

The following examples are illustrative of aerosol antiperspirant compositions, prepared according to the inven- 4 tion, wherein a single alkane formed in the container provides the propellant system.

EXAMPLE 1 In a purged bottle place: isopropanol, 99% -|-77.0 grams Crimp on valve and pressure fill the container with: diisobutylaluminum chloride-10.0 grams Upon actuation of the valve, this aerosol container dispenses di-isopropoxy aluminum chloride as an antiperspirant with isobutane as the propellant.

EXAMPLE 2 In a purged bottle place:

Grams Isopropanol, 99%+ 52.0 Chloroform 25.

In a purged bottle place 70.1 grams of a solution containing:

Grams Lauryl alcohol 25.2 Absolute ethanol 0.5

Hexane 10.0

Chloroform 34.4

Crimp on valve and pressure fill with:

Grams Dibutylaluminum chloride 9.0

Methylene chloride 25.0

Upon actuation of the valve, this aerosol container dispenses dilaurylal-uminum chloride as an antiperspirant with a mixture of butane and hexane as the propellant.

EXAMPLE 4 -In a purged bottle place:

Grams Tertiary butyl alcohol 7.6 Isopropanol 19.4 Trichlorofluoromethane 25.0

Crimp on valve and pressure fill with: Dipropylaluminum chloride, 25% solution in hexane34.0 grams.

Upon actuation of the valve, this aerosol container dispenses di-tert-b-utoxy aluminum chloride as an antiperspirant with a mixture of propane and hexane as the propellant.

EXAMPLE 5 In a purged bottle place:

Grams Tertiary butyl alcohol 3.8

Chloroform 63.3

Crimp on valve and pressure fill with:

Grams Di-isobutylaluminum chloride, 25 solution in hexane 18.0 Isobutane 14.0

Upon actuation of the valve, this aerosol container dispenses di-tert-butoxy aluminum chloride as an antiperspirant with a mixture of isobutane and hexane as the propellant.

EXAMPLE 6 In a purged bottle place:

Grams Isopropanol, 99%+ 44.5 Trichlorofluoromethane 32.3

Crimp on valve and pressure fill with:

Grams Di-isobutylaluminum chloride, 25% solution in hexane 18.2 Isobutane 6.0

Upon actuation of the valve, this aerosol container dispenses di-isopropoxy aluminum chloride as an antiperspirant with a mixture of isobutane and hexane as the propellant.

The subject matter which the applicant regards as his invention is particularly pointed out and distinctly claimed as follows.

I claim:

1. A method for preparing a package adapted to dispense in aerosol form a self-propelling pressurized antiperspirant composition comprising the successive introduction of an alkanol of from 1 to 18 carbon atoms and an alkyl aluminum chloride having alkyl radicals of from 3 to 4 carbon atoms into an aerosol container equipped with a cap having a valve adapted for both filling and dispensing the contents of the container, at least one mole of said alkanol being present to react 6 with each alkyl radical present in one mole of said alkyl aluminum chloride, wherein at least one of said alkanol and alkyl aluminum chloride is introduced into said container through said valve after said cap has been affixed to said container; said alkanol and said alkyl aluminum chloride reacting chemically within said container to form an alkoxy aluminum chloride antiperspirant of from 1 to 18 carbon atoms and an alkane propellant of from 3 to 4 carbon atoms, excess alkanol remaining unreacted and acting as a solvent for said aluminum chloride antiperspirant.

References Cited UNITED STATES PATENTS 3,036,743 5/ 1962 Rhodes et a1 222394 ALBERT T. MEYERS, Primary Examiner A. I. ROBINSON, Assistant Examiner US. Cl. X.R. 

